Facilitating computer-aided detection, comparison, or display of medical images

Abstract

The present invention is methods for processing medical images so as to remove certain effects of the physical characteristics of the object being imaged and/or of the apparatus used to form the images. The invention further provides for the formation of a standardized image from the processed image and for the use of the standardized image or the processed image in the training of computer-aided detection/diagnosis algorithms. These algorithms may then be used to detect abnormalities in other standardized or processed images derived from any of a variety of image acquisition systems.

1. A method for processing mammographic images comprising the steps of:
 forming in a first mammography system a digital or digitized mammogram of a breast along with images of first and second reference materials having thicknesses that range from 0 to the thickness of the breast, one reference material having an attenuation constant that is approximately the same as that of fat and the other having an attenuation constant that is approximately the same as that of glandular tissue; 
 using exposure information in the images of the first and second reference materials to process the digital or digitized mammogram system to transform the digital or digitized mammogram into a first processed image whereby substantially all effects related to the physical characteristics of the first mammography system and its operating parameters and the effect of fat content in the breast being imaged are removed; 
 transforming the first processed image into a standard-form mammogram having pixel values that would have been obtained by a standard-form mammography system having a first standard x-ray voltage parameter and a first standard exposure parameter; and 
 storing said standard-form mammogram
 whereby visual comparison of mammograms taken by different mammography systems is facilitated by comparing standard-form mammograms derived from mammograms taken by the different mammography systems. 
 
 
   
   
     2. The method of  claim 1  wherein the processing removes distinguishing effects of both of the following operating parameters of the mammography system, wherein the distinguishing effects are related to at least one of:
 x-ray energy; 
 exposure. 
 
   
   
     3. The method of  claim 1  wherein the standard x-ray voltage parameter is in the range 25-28 kVp. 
   
   
     4. The method of  claim 1  wherein the standard exposure is in the range of 20-200 milli-Ampere-seconds.